From 2003 to 2005, Mankiw was chairman of the Council of Economic Advisers under President George W. Bush. In 2006, he became an economic adviser to Mitt Romney and continued during Romney's 2012 presidential bid.[1][2] He is a conservative[3][4][5][6] and he writes a popular blog[7], ranked the number one economics blog by US economics professors in a 2011 survey.[8] He is also author of the best-selling textbook Principles of Economics. The IDEAS/RePEc overall ranking puts him as 42nd most influential economist in the world today; as measured by the h-index, he is the 14th most productive research economist.[9] In 2007 he was elected a member of the American Academy of Arts and Sciences. Along with David Card, he was elected vice president of the American Economic Association for 2014.

He was appointed by President George W. Bush as Chairman of the Council of Economic Advisers in May 2003. He has since resumed teaching at Harvard, taking over the most popular class at Harvard College, the introductory economics course Ec 10.[15]

He has written two popular college-level textbooks: one in intermediate macroeconomics and the more famous Principles of Economics. More than one million copies of the books have been sold in seventeen languages.[citation needed]

Mankiw has become an influential figure in the blogosphere and online journalism since launching his blog. The blog[7], originally designed to assist his Ec10 students, has gained a readership that extends far beyond students of introductory economics.[17] In particular, he has used it as a platform to advocate the implementation of pigovian taxes such as a revenue-neutral carbon tax; to this end Mankiw founded the informal Pigou Club.[18]

Several controversies arose from CEA's February 2004 Economic Report of the President.[22] In a press conference, Mankiw spoke of the gains from free trade, noting that outsourcing of jobs by U.S. companies is "probably a plus for the economy in the long run."[23][24] While this reflected mainstream economic analysis, it was criticized by many politicians[25][26] who drew a link between outsourcing and the still-slow recovery of the U.S. labor market in early 2004.[26]

Controversy also arose from a rhetorical question posed by the report (and repeated by Mankiw in a speech about the report):[27] "when a fast-food restaurant sells a hamburger, is it providing a service or combining inputs to manufacture a product?" The intended point was that the distinction between manufacturing jobs and service industry jobs is somewhat arbitrary and therefore a poor basis for policy. Even though the issue was not raised in the report, a news account led to criticism that the Administration was seeking to cover up job losses in manufacturing by redefining jobs such as cooking hamburgers as manufacturing.[28]

"If you were going to turn to only one economist to understand the problems facing the economy, there is little doubt that the economist would be John Maynard Keynes. Although Keynes died more than a half-century ago, his diagnosis of recessions and depressions remains the foundation of modern macroeconomics. His insights go a long way toward explaining the challenges we now confront."[29]

Mankiw has expressed skepticism about a trillion dollar spending package in the face of the global financial and economic crisis. He has vigorously criticized Vice-President Joseph Biden for suggesting there was complete unanimity of support among economists for a stimulus package.[30]

On November 2, 2011, a number of students in Mankiw's Economics 10 class walked out of his lecture. Several dozen of the 750 students participated.[31][32] Before leaving, they handed Mankiw an open letter critical of his course, saying in part:

"we found a course that espouses a specific—and limited—view of economics that we believe perpetuates problematic and inefficient systems of economic inequality in our society today ... Economics 10 makes it difficult for subsequent economics courses to teach effectively as it offers only one heavily skewed perspective rather than a solid grounding on which other courses can expand. ... Harvard graduates play major roles in the financial institutions and in shaping public policy around the world. If Harvard fails to equip its students with a broad and critical understanding of economics, their actions are likely to harm the global financial system. The last five years of economic turmoil have been proof enough of this."[33]

The students concluded their letter by stating they would instead be attending the Occupy Boston demonstration then under way. Counter protesters showed up in that class and Mankiw replied to his students in an article in The New York Times.[34][35] An editorial in the student-run Harvard Crimson condemned the protest.[36] Harvard Crimson in its editorial stated that:

"While it is true that Professor N. Gregory Mankiw, who was lecturing during the walkout, has conservative views and held a position in the Bush Administration, we take issue with the claim that his class is inherently biased because he is the professor and author of its textbook. The truth is that Ec 10, a requirement for economics concentrators, provides a necessary academic grounding for the study of economics as a social science. Professor Mankiw’s curriculum sticks to the basics of economic theory without straying into partisan debate. We struggle to believe that we must defend his textbook, much maligned by the protesters, which is both peer reviewed and widely used.

Furthermore, the students protesting the class who desire that he give more time to other, less accepted schools of economic thought—like Marxism—would do well to remember that such interrogation is the domain of social theory, not economic theory. Supply-and-demand economics is a popular idea of how society is organized, and Mankiw’s Ec 10 never presents itself as more than that. As such, including other theories would simply muddy the waters of what is intended; Ec 10 is an introductory class that lays the foundation for future, more nuanced, study.

That being said, even if Ec 10 were as biased as the protesters claim it is, students walking out to protest its ideology set a dangerous precedent in an academic institution that prides itself on open discourse. This type of protest ignores opposition rather than engages with it. Instead of challenging a professor to back up his claims, it tries to remove him from the dialogue."